Public Executive Summary of the Open Space Innovation Platform Project leaded by Vulkam with Thales Cryogenics BV and Lynred
First of all, we would like to deeply thank ESA-OSiP teams for their financial, technical and administrative support during our exploratory activity
The Program in a nutshell
- Vulkam, a French high-tech start-up specialized in amorphous metallic alloys (AMA), has developed a new range of materials with mechanical and thermal properties superior to those of Ti6Al4V. Vulkam is the only European company focusing on the industrialization and optimization of amorphous metals.
- As we know, improving the efficiency of a cryogenic cooler is of great interest to ESA. Heat conduction losses in the cold finger of cryogenic coolers are one of the main causes of their lack of efficiency.
- Vulkam, Lynred and Thales Cryogenics have proposed to ESA a 12 months OSiP evaluation study to assess the potential of these new materials in compact space cryocoolers.
Main Steps conducted during the study:
1.Theoretical study: thermal analysis on current product, design and structural analysis of PoC demonstrator, approval approach baseline proposal
2.Joining optimisation and qualification of the brazing method on simple parts
3. Manufacturing of parts and assembling demonstrators (+vérifications)
4.Testing of final samples
Main results and achievements
1.The great expectations about thermal conductivity / losses and general behaviour of the Vulkalloy Zr4 have been validated
- Consistency between thermal analysis and thermal loss evaluation on demonstrators : 1,8 reduction achieved
- More than 50% of reduction of thermal parasitic losses
- A significant increase of ‘available cooling power’ for the same input power
2.For the first time, deep understanding of brazing behaviour between an amorphous metal and different cristalline alloys has been achieved
- Preparation process and metallization have been improved for Vulkalloy® and each materials in regards of Vulkalloy® : An optimal configuration has been found for each base material thanks to this study
- Manufacturing of parts used for demonstrators have been planned according to the results of this study
3.Mechanical performance testing not yet conclusive… But we have some significant clues for further investigation
- One of the tested configuration appear promising (not far from passing)
- Joints are points with lowest MOS, not the AMA pipe
- Multiple isolated key findings will lead to compliancy if properly assembled
4.Conclusion & perspectives:
- Thermal analysis shows significant improvement on thermal efficiency and performance, demonstrated by boil-off measurements on samples
- Process optimizations, analysis and qualifications necessary on final application
